Relative angle sensing device and electric power steering apparatus

Abstract

A relative angle sensing device is provided with: a sensor that is contained in a housing in which a communication hole communicating inside and outside is formed, and outputs an electric signal according to relative rotation angle between two rotary shafts coaxially arranged; an electric cable that transmits the electric signal outputted from the sensor to an apparatus arranged at outside of the housing; an electric cable holding member that is fitted with the communication hole of the housing and holds the electric cable; and an outer component that is arranged at a position outside the electric cable holding member in the communication hole of the housing, and that has, at inside thereof, a penetration hole through which the electric cable passes. The outer component has a pair of opening and closing components that is joined by a hinge and opens and closes the penetration hole by relative rotation.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is based on and claims priority under 35 USC §119 from Japanese Patent Applications No. 2011-262716 filed Nov. 30, 2011, No. 2011-262717 filed Nov. 30, 2011, No. 2012-087448 filed Apr. 6, 2012, and No. 2012-087449 filed Apr. 6, 2012.BACKGROUND[0002]1. Technical Field[0003]The present invention relates to a relative angle sensing device and an electric power steering apparatus.[0004]2. Related Art[0005]Recently, there has been suggested a device for sensing a relative rotation angle between two rotary shafts coaxially arranged.[0006]For example, a device described in Japanese Patent Application Laid Open Publication No. 2007-187589 is provided with: two magnetism collecting rings that are arranged around the outer periphery of a magnetic circuit formation component contained in a first rotating body and a second rotating body coaxially connected by a torsion bar so as to be isolated in an axial line direction, and collect ...

AI Technical Summary

Benefits of technology

The present invention suggests an apparatus that prevents force from being applied to the electric cable holding part of an electric cable holding member and the end of an electric cable in a housing, even if there is force applied outside of the housing. This is achieved through a simple configuration that includes a plate made of sheet metal placed outside of the housing. The invention also maintains a sealing property of the communication hole of the housing by preventing force applied at the outside of the housing from being directed to the electric cable holding part. This reduces the risk of electrochemical corrosion between the plate and the housing. Overall, the invention provides a safer and more reliable apparatus for protecting electric cables in housings.

Problems solved by technology

For example, in the case where the end of the electric cable is connected to a connecter and the connector is inserted into a connecting terminal, if strong force is applied to the end of the electric cable in the housing, there is a possibility that the electric cable may come off the connector or the connecting terminal to which the connector has been inserted may be broken.

In addition, there is a possibility that a sealing property of the electric cable in the electric cable holding member (grommet) may be deteriorated due to application of force on the electric cable at the outside of the housing.

Moreover, there is a possibility that the electric cable holding member (grommet) may come off the communication hole due to the application of force on the electric cable at the outside of the housing.

However, in this configuration, in the case where the housing is composed of aluminum, there is a possibility that the electric cable holding member (grommet) may be dropped due to occurrence of electrochemical corrosion between the plate and the housing.

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